Inner cover for annealing furnaces



H. F. RADLINSKI ETAL Dec. 8 1959 INNER COVER FOR ANNEALING FURNACES Filed March 22, 1954 United States Patent INNER COVER FOR ANNEALING FURNACES Harry F. Radlinski and Harold E. Conover, Toledo, Ohio, assignors to Surface Combustion Corporation, Toledo, Ohio, a corporation of Ohio Application March 22, 1954, Serial No. 417,646

6 Claims. (Cl. 263-49) This invention relates to inner covers for annealing furnaces, and more particularly to circular covers and means for lifting and transporting the same.

Such covers are commonly used on bell type furnaces, and are closely spaced from coils of strip, stacked inside the cover, to be heated. Rapid heating and cooling of the coils is accomplished by rapid circulation of gases inside the inner cover and radiation of heat to the outside thereof, as is explained in patent to Cone, 2,600,094. Some difficulty has been encountered in making such covers sufficiently light for transportation thereof and for good heat transfer properties, and yet sufliciently sturdy and stable in shape to be raised by means supported overhead, such as crane operated tongs, withont distortion. This problem is especially present in vertically corrugated circular covers because of the reduction of stability inherent in corrugating a circular wall. Circular inner annealing covers also constitute an operating hazard on the mill floor because they are generally much higher than a man and are commonly made of mild steel which in time forms surface scale. The covers are so high that such scale may drop onto men nearby on the mill floor. Where a floor operator is necessary to guide lift tongs into lift brackets on the cover, and the floor operator must look up to do so, he is in danger of getting mill scale into his eyes even through wearing safety goggles of any of the various usual designs. Mill scale is often forced oif of the cover surfaces due to contact by the lift tongs with the cover, and also due to distortion of the cover due to the lifting forces applied thereto.

This invention presents a solution to these problems in providing a more stable cover and in providing a cover and lift tongs therefor which eliminate the need for a floor operator for attaching the tongs.

For a consideration of what we believe to be novel and our invention, attention is directed to the following portion of the specification, the drawing, and the claims thereof.

In the drawing:

Fig. 1 shows an inner cover according to this invention.

Fig. 2 is a partially broken away plan view of the cover of Fig. 1.

Fig. 3 is a sectional view of a portion of the cover of Fig. 1.

Fig. 4 is a plan view of cover lifting apparatus shown in lifting position on the cover of Fig. 1.

Fig. 5 is a front elevational view of the apparatus of Fig. 4.

Fig. 6 is a side elevational view of a portion of the apparatus of Fig. 4.

The inner cover of Figs. 1, 2 and 3, comprises a top, circular sidewalls, and a circular channel member between the top and side walls and forming an outwardly facing channel or groove.

The lift tong apparatus of Figs. 4, 5 and 6 comprise substantially parallel bars adapted to slide into the channel on opposite sides of the cover and to lift the cover by acting on the upper surface of the channel, or the upper-- flange of the channel member. The bars each have an; upturned leading edge and a turned in trailing edge to serve as stops to position the bars in the cover channel.

The inner cover illustrated in Fig. 1 comprises a vertically corrugated side wall 11, reinforced by bands 12 secured to the outer convolutions of the side wall at spaced intervals, a depending skirt 13 at the foot or bottom of the cover for insertion into an atmosphere seal trough, and a dished top plate 14. A circular, relatively heavy channel member 15, having an upper flange and a web body portion forming a relatively strong angle in the member, is inserted between the top plate 14 and the corrugated side wall 11, to lend strength and stability of form to the cover and to provide means for lifting the cover without warping the same. The lower flange of the channel 15 forms an annular ring for attachment to the corrugated side wall, preferably by continuous, gas tight welding. The lower skirt 13 is also preferably formed of an angle in circular form providing an annular ring surface for similar attachment to the bottom of the corrugated side wall 11.

In Fig. 2 the plan view shows the dished top 14, and in a cut away portion the corrugated side wall 11 is shown by a single heavy line. The channel member 15 is disposed between the side wall 11 and the top 14 and welded to each to form a gas tight inner annealing cover.

In Fig. 3 a portion of the side wall 11 is shown in some detail to show its convolutions.

In Figs. 4 and 5 a lift tong assembly for lifting the cover is shown, comprising a pair of specially formed, substantially parallel bars 21 constitute a lift fork adapted to straddle the web portion of the circular channel member 15 in its outwardly facing groove. The leading ends of the bars 21 are inclined upwardly to assist in centering the bars, and the trailing ends of the bars are inclined towards each other to serve as stops for positioning the bars in the channel groove. The trailing ends could alternatively bend up or down for this purpose. The bars 21 are supported by vertical straps 22 which are in turn supported by gusset members 23, a tension and guide plate 24, vertical lift bar supports 25 and a lift bar 26 adapted to receive a lift hook from an overhead crane. y

In Fig. 4 the lift tong assembly is shown with the bars 21 positioned in the channel of the cover. The trailing edges of the bars turn inwardly to contact the channel member 15 and serve as a stop in initially positioning the bars 21, and in Fig. 5 the top 14 and the channel member 15 are shown in dashed lines in relation to the up turned leading ends of the bars 21.

Fig. 6 shows a profile of a bar 21 with its upturned leading end. As the tong assembly is lifted by a hook placed about the lift bar 26, the bars 21 tend to center on a diameter of the cover, and with the stability of shape inherent in the heavy channel member 15, the tendency to warp the cover side walls 11 is substantially eliminated.

Since repeated lifting is not necessarily done from the same peripheral points on the channel member 15, no cumulative working elfect is obtained as is the case where the cover is provided with the usual lift straps. It will be appreciated that the lift tong assembly is adapted foroperation by a crane operator with no assistance from the In practice, the crane operator drops. the lift tong assembly onto the edge of an inner cover top so that the guide plate 24 contacts the top 14 nearthe edge thereof and the upturned leading edges of the The plate 24 and the bars 21 are vertically spaced to place the bars 21 in line with the web portion of the channel mernber 15 when the plate 24 is on, or nearly on, the top 14.

annealing floor.

bars 21 face toward the center of the cover.

Patented Dec. 8, 1959' The crane operator then need only move the crane hook towards the centerline of the cover and the tong assembly will lean slightly in that direction and slip into place for lifting, and with no assistance from the mill annealing floor near the covers.

This cover and lift tong assembly design reduces warp-- age of the cover, reduces hazardous conditions on the mill floor, eliminates the need for a mill floor operator in. attaching lift tongs, and also reduces the cover sidewall area for heat transfer adjacent the top and thus serves. to avoid overheating the top of the top coil in the area. where the top radiates heat to the coil; hence this design and invention is Well suited to its intended purpose.

We claim:

1. An inner cover for annealing furnaces comprising: a vertically corrugated, circular side wall; a circular band around the periphery of the side wall subjacent the bot tom thereof; a circular channel shaped member superjacent the top of the side wall and forming an outwardly facing circular channel around the periphery of the cover and having a bottom flange of a width .at least equal to the depth of the corrugations; and a top closure for the inner cover.

2. An inner cover for annealing furnaces, comprising: a vertically corrugated circular side wall; a circular band around the periphery of the side wall adjacent the bottom thereof; a relatively heavy, compared to said side wall, stable channel member having an upper flange and a web body portion forming a stable circular angle portion about the cover, and secured to the top of the side wall; and a top closure for the inner cover.

3. A circular inner cover comprising a metallic main wall having a continuous series of uniform corrugations arranged circumferentially of the cover and extending from a point adjacent the bottom to a point adjacent the top of the cover, a bottom metallic member secured to the bottom of the main wall, said bottom metallic member having a portion sealing the bottom of said corrugations and a downwardly extending ring, a top metallic member secured to the top of the main wall, said top metallic member having a portion sealing the top of said corrugations and a cylindrical ring portion of sufficient vertical height to receive the jaws of a tong, and a cover secured to the top of said top member.

4. A circular inner cover comprising a metallic main wall having a continuous series of uniform corrugations arranged circumferentially of the cover and extending from a point adjacent the bottom to a point adjacent the top of the cover, a metallic angular member having a generally horizontal outwardly facing leg and a downwardly extending generally vertical leg, the said horizontal leg being fastened to the bottom of the corrugations and having a width at least equal to the depths of the corrugations, a circular channel shaped metallic member secured to the top of the corrugations with the legs thereof facing outwardly, the Width of the bottom leg of said channel member being at least equal to the depth of the corrugations, the legs :of said channel member being spaced apart a sufiicient distance to receive the jaws of a. gong and a coversecuredtothe top of said channel mem- 5. A circular inner acover c'omprising a metallic :m'ain wall having a continuous series of uniform corrugations arranged circumferentially of the cover and extending from a point adjacent theb'ottom to a point adjacent the top of the cover, .a bottom metallic member secured to the bottom of the main wall, said bottom metallic member having a portion sealing the bottom of said corrugations and a downwardly extending ring, a circular channel shaped metallic member secured to the top of the corrugationswith the legsthereof facing outwardly, the width of the bottom leg of said channel member being at least equal to the depth of the corrugations, the legs of said channel member being spaced apart a sufiicient distance to receive the jaws of a tong, and a cover secured to the top of said channel member.

6. A circular inner cover comprising a metallic main wall having a continuous series of uniform corrugations arranged 'circumferentially of the cover and extending from a point adjacent the bottom to a point adjacent the top of the cover, a top metallic member secured to the top of the main wall, said top metallic member having a portion sealing the top of said corrugations and a cylindrical ring portion of sufficient vertical height to receive the jaws of a tong, 'anda cover secured to the top of said top member.

ReferencesCited in the file of this patent UNITED STATES PATENTS 268,128 Roberts Nov. 28, 1882 682,459 Demmler Sept. 10, 1901 700,962 Markey May 27, 1902 1,624,799 Neilson Apr. 12, 1927 2,300,370 Lowery Oct. 27, 1942 2,452,931 Jacob Nov. 2, 1948 2,581,923 .Hall Sept. 13, 1949 2,510,596 Murphy June 6, 1950 2,529,609 Jacob Nov. 14, 1950 2,541,511 Guzel Feb. 13, 1951 FOREIGN PATENTS 288,268 Italy Sept. 2, 1931 

